1. Field of Invention
The present invention relates to an electrical connector, especially to a socket terminal for grip array connector, and connecting chip modules with circuit boards.
2. Description of Related Art
Along with prosperous development of electronic industries, electrical connectors have become more important and with broader applications in this field. Thus there are two important factors for people in this field to select proper electrical connectors-performance and cost of the electrical connector. Some other issues are also taken into considerations such as how to provide better electrical connection between the terminals of the electrical connector and electronic components/circuit boards, how to reduce cost of electrical connectors and improved manufacturing efficiency, and factors that affect performance or cost of the electrical connector. One of the factors is the shape and structure of the terminal of the electrical connectors.
Refer to Chinese Pat. No. 01279922, a conductive terminal of electrical connectors is disclosed. The conductive terminal includes a base and two arms. The base includes a main body and a welding part that connects a conductive terminal of the electrical connector to a circuit board. The two arms are bent from two opposite sides of the main body. Each arm consists of a connection part extending upwardly from the main body and disposed on opposite sides, a contact part arranged at a rear end of the connection part, and a guiding part extending from one side of the contact part near the main body. A receiving space is formed between the two connection parts. The two connection parts are parallel while extending upward and the two contact parts are also parallel to each other. Pins of chip modules are toward the contact part by the guiding of the guiding part so as to electrically connect with the conductive terminal of the electrical connector.
The two connection parts are parallel while extending upward and the two contact parts are also parallel to each other. The two contact parts are respectively formed at a rear end of the each connection parts so that the distance between the two contact parts is the same with the distance between the two connection parts.
The above conductive terminal of the electrical connector has following shortcomings:                1. Because the distance between the two contact parts is the same with the distance between the two connection parts, the pin size can only be smaller or equal to the distance between the two connection parts.        2. The sharp end of the pin is easy to scratch inner walls of the two arms and cause damages of the pin as well as the conductive terminal of the electrical connector. Thus both the electrical connection between the conductive terminal of the electrical connector and the chip module, and the electrical connection between the conductive terminal of the electrical connector and the circuit board are further affected.        
Refer to U.S. Pat. No. 6,319,038, a contact (terminal) for another connector is revealed. The contact includes a base, a pair of contact regions for electrically connected with a chip module and a pair of arm sections extending from the base. Each arm section comprises an upper arm extending from the base, a forearm extending from a free end of the upper arm for connecting the upper arm with a contact region, and a palm extending from the contact region toward the base. The distance between the pair of forearms is smaller than the distance between the two upper arms but larger than the distance between the two contact regions.
When the conductive terminals are aligned on a metal band and the pair of arms is in the same plane as the base, the two arms are totally formed by bending of material on left and right sides of the base inwards. Thus the width of each conductive terminal occupied on the metal band is increased. That means the distance between central lines of two contiguous conductive terminals is increased and the total extended area of the conductive terminal is enlarged. During the assembling processes, the conductive terminal is assembled into the terminal receiving slot with the metal band in an alignment. Under the limit of the shape of the conductive terminal of the electrical connector, the distance of the above two contiguous conductive terminals is unable to be reduced or adjusted according to the distance between central lines of the two contiguous terminal receiving slots.
According to the above structure, when the pins of the chip module connect with the conductive terminal of the electrical connector, the pin size can be adjusted properly because the distance between the pair of upper arms is larger than the distance between the two contact regions. At the same time, the sharp end of the pin will not damage inner walls of the two upper arms so that damages of pins and of conductive terminals can be avoided.
Although the above conductive terminal solves the problems of damages of pins as well as the conductive terminal, such design still has some disadvantages:                1. Considering the cost, the material is wasted because the two arms are totally formed by material on left and right sides of the base and then being bent inwards. Furthermore, the distance between the central lines of two contiguous conductive terminals of electrical connectors is increased.        2. In consideration of time: during the assembling processes, the conductive terminals of the electrical connector connected with the metal band are assembled into the terminal receiving slot in a line. Under the limit of the shape of the conductive terminal, the distance of the above two contiguous conductive terminals is unable to be reduced along with the shortened distance between central lines of the two contiguous terminal receiving slots. This increases the level of difficulty in assembling and reduces the efficiency of stamping as well as assembling. Thus the manufacturing cost is increased.        
Thus is a need to design a novel electrical connector to overcome the shortcomings mentioned above.